Signaling system



m 15, 1940. A u; 2,217,769

I SIGNALING SYSTEM Filed llarch 24. 1939 4 Sheath-Sheet 1 FIG.

mus NORMALLY CLOSED av SOLENOID 4m; ope--50 BY SPRING VALVE NORMALLY CLOSED 8 SOLENOID AND OPENED BY SPRING VALVE NORMALLY CLOSED BY SOLENOID AND OPENED 8) SPRING INVEN TOR By A./-. PRICE ATTORNEF Oct. 15, 1940. PR|E 2,217,769

' sternum SYSTEM Filed larch 24 19:59 4 Sheets-Sheet 2 VALVE NORMALLY CLOSED 5) SPRING AND OPENED BY SOLENOID VALVE NORMALLY CLOSED 8) SPRING AND OPENED BY SOLENOID VALVE NORMALU CLOSED BY SPRING AND OPENED BY SOLENOID nvvs/v TOR Af PRICE ATTORNEY Oct. 15, 1940 A. F. PRICE 7,

' I SIGNALING SYSTEM Filed March 24, 1939 4 Sheets-Sheet 3 FIG. 3

VALVE NORMALLY CLOSED DY SOLENOID AND OPENED BY'SPfl/NG VALVE NORMALLV CLOSED BY SOLENOID AND OPENED BY SPRING VALVE NORMALLV CLOSED 8V SOLENO/D.AND OPENED 8) SPRING I INVENTOR ARPR/CE' ATTORNEY Oct. 15, 1940. A. F. PRICE 2, 7,

' smmmne SYSTEM Filed larch 24, 1939 4 Shqets-Sheet 4 INVENTOR- By A .F. PRICE WWW A TTORNEV Patented on. is, 1940 1 UNITED STATES PATENT OFFICE T 2,211,100 l BIGNAIJNG srs'mu Arnold r. in... 1mm, N. r. aasignor when -'Ielephone laboratories, Incorporated, New

York, N. Y.,acorporation otNcwYork Application March a4, 1939, Serial No. coasts 6 cwms. (CL 179-484) This invention relates to signaling systems and particularly to those in which any desired number of the signal receiving devices may be connected to-any one of several signal transmitting 6 circuits.

In certain applications of systems of this type, the loud-speakers are sometimes subjected. to such abnormally high air pressures that it is desirable to protect the vibratory diaphragms 1 of the loudspeakers when they are not in use by a valve'which normally closes the opening through which the sound energy is radiated. Gne such valve is disclosed .in Patent 2,098,291 to Hopkins, November 9, 1937. When the blast valve is closed the loud-speaker is,'of course, inoperative and hence the valve is designed to be either opened or closed by energizing a solenoid, depending on whether protection of the loudspeaker or operativeness of the systemlin emer- W gencies is the primary consideration. If, for example, a solenoid holds the valve closed against the tension of a spring, thevalve will open autoj matically when the power fails leaving the loudspeaker. unprotected but in operative condition.

-The object of this invention is a control circuit-which will quickly condition for operation any selected number of the receiving devices in such a system'and which will keep all of the devices protected when they are not actually in '80 use.

According to the invention, the blast valves of, all the loud-speakers oi the system are controlled from any transmitting station ov'er solenoid energizing circuits which include contacts on the corresponding loud -speaker selecting switch at each station. As each loud-speaker is selected for operation at anystation', the con-' trol circuit for its solenoid is extended to the contacts of a relay common to all the selecting '4'0 switches at that station. When the transmitter is energized for announcing purposes this relay is operated and the blast valves'of all the selected loud-speakers are opened to condition the loud? speakers for operation. With a circuit of this type the blast valves the loud-speakers;

are controlled by means of a single relay ateach'station regardless of the Fig. 3 shows a system'similar to Fig. 2 but 3 adapted to open the valves by deenergizing the solenoids as in Fig. 1; and a Fig. 4 shows how the circuit of Fig. 1 may be extended to a system involving any number'ot 5 transmitting stations. I v I Referring now toFlg.'1, the system showncomprises two transmitting stations I and 2 and v a plurality of loud-speakers such as and I. Each transmitting station is provided with a id transmitter 5, a transmitter switc i, anam-i plifler I and a plurality of loud-ape er selecting keys, such as I, 9 at station 1 and II, II at station 2, for selectively connecting the loud-speakers to the amplifier. 1

The loud-speakers are p vlded with protecting valves of the type shown in the Hopkins patent referred to above which consistessentially p of a solenoid 12 which. when energized, moves the plug 13 against the tension of the spring M ii) into the throat of the loud-speaker horn as shown. With all of the selecting keys in the non-selected position as shown, the solenoid I! of loudspeaker? 3, for example, is energized over a-circuit extending irom one terminal of the power supply 28 a" a through contact I! of switch I at station i to one side of the solenoid and from the other end of the solenoid windingthrough contact I. of switch I! at station 2 to the other terminal of the power supply. The solenoid of loud-speaker I is also energized over a similar circuitincluding contact H on the switch 9 and contact II on switch ii.

When the switches 8 and 9 are operated to connect the loud-speakers 8, and l tothe amplifier I, 7 contacts lo and II are opened but contacts ll and 20 are closed, thereby completing holding circuits ior the solenoids through. the contact 2! of relay 22. Similarly, if switches II and II are operated to connect the loud-speakers to the am- I plifler of station 2, contacts ll and 18 are opened '10 and the solenoids are contact-23 of relay 24. When the operator at station i, for example. desires to make an announcement. he operates and holds his transmitter switch 0 which connects co the transmitter 5 to the input of the amplifier I and at the-same timecompletes a circuit through then energized through contact 25 for-the relay 2!. The operation of relay 2! opens at wntact 2| the solenoid circuits .of all the loud-speakers which have been selected so at that station, thereby permitting their-valves to open and condition the loud-speakers to reproduce the announcement. As scenes the transmitter switch is released contact "reopens, relay *2 releases and closes the solenoid circuits of the u solenoid circuit of all the loud-speakers connected to the transmitter, and a switch for energizing the transmitter and controlling the relay. a plurality of v 3. In an announcing system, loud-speakers each having a vibratory diaphragm, a valve ior sealing the diaphragm against abnormal atmospheric pressures and a solenoid for closing the valve, tions each including a transmitter and a twoposition switch for each loud-speaker for selectively connecting the loud-speaker to the transmitter, a circuit including contacts on the corresponding at both stations for energizing each solenoid for both positions of said switches, a relay at each station having normally closed contacts common to the solenoid circuits of all loud-speakers connected to the transmitter, and a switch at each station for controlling the relay.

4. In a signaling system,.a signal transmitter a plurality of normally inoperative signal receiving devices, a signal circuit including a switch at the transmitter for each device for selectively connecting it to the transmitter, means at each' device for conditioning it for operation, an operating circuit for each conditioning means including contacts on the corresponding switch at the transmitter, and means common to all the switches in their selected positions for controlling all of the operating circuits.

two transmitting staloud-speaker selecting switches 5. In'a signaling system, a plurality of transmitting stations each having a signal transmitter, a plurality of receiving devices, switching means at each station foreach device for selectively connecting the device to and disconnecting it from the signal transmitter, a solenoid for each device for normally maintaining it in inoperative condition, a source of current, an energizing circuit for each solenoid comprising two conductors each normally extending between the solenoid and the source of current through the switching means at a plurality of stations for the corresponding receiving device, normally closed contacts at each station connecting the source of current directly to each switching means to maintain the solenoid energizing circuits of the receiving devices when connected to the transmitter, and means at each station for energizing the transmitter and opening the contacts.

6. In a. signaling system, a plurality of transmitting stations, a signal transmitter at each station, a plurality of signal receiving devices, a solenoid for each device for normally maintaining it in inoperative condition, two-position switching means at each station for selectively connecting the transmitter to each device, energizing circuits including closed contacts in a for each solenoid both positions of the corresponding switching means, and means at each station for simultaneously opening the solenoid circuits of all the receiving devices connected to the transmitter.

ARNOLD F. PRICE. 

